1,1'-Carbonyldiimidazole → 8,8,11,14,14-Pentamethyl-7,12-dioxo-1,1,1-triphenyl-13-oxa-6,11-diaza-1-phosphoniapentadecane bromide

Participants

Reaction Steps

4-[(tert-butoxycarbonyl)(methyl)amino]-2,2-dimethylbutanoic acid (Organic and Molecular Chemistry, 2011, 9, 1846-1854, 117 mg, 0.48 mmol) was dissolved in N,N-dimethylformamide (1.2 mL) and treated with N,N-carbonyldiimidazole (104 mg, 0.64 mmol). The mixture was stirred at room temperature for 30 minutes. (4-Aminobutyl)(triphenyl)phosphonium bromide (277 mg, 0.67 mmol) was added, and the reaction was stirred overnight at room temperature. The reaction mixture was then diluted with methylene chloride and washed with 5% aqueous lithium chloride (3 times), 1N aqueous hydrogen chloride, and saturated sodium bicarbonate. The organic solution was dried over anhydrous sodium sulfate, filtered, and concentrated to give the title compound (210 mg, 69%) as a white foam. Sample was used crude in next step.

Provenance & Evidence